FISHERIES

12. FISHERIES

12.1 Introduction

12.1.1 This chapter assesses the impacts of the Project upon fisheries.

12.1.2 The Project consists of the provision of a drainage tunnel and collecting system for the Northern Hong Kong Island as well as a submarine outfall at Cyber Port. The outfall includes a stilling basin to release the surface runoff arising from the Hong Kong Island catchment area to the Lamma Channel.

12.1.3 The objective of this assessment is to identify existing fisheries resources in the Study Area so as to evaluate any impacts of the Project at both construction and operational phases and where required to propose mitigation measures to minimize adverse impacts. The assessment follows the criteria and guidelines as stated in Annexes 9 and 17 of the EIAO TM and the EIA Study Brief No. ESB-070/2001.

12.1.4 The assessment is mainly focused on the outlet structures at the proposed Hong Kong West Drainage Tunnel and the receiving water body. The impacts from above-ground intake structures along the tunnel are covered by the chapter for terrestrial ecological assessment in this report and not considered to be significant for fisheries.

12.1.5 The nature and scope of the Project is described in Section 2 of this Report. In accordance with the EIA Study Brief No. ESB-070/2001, this section identifies and assesses the fisheries impact associated with the Designated Project described in Section 2.

12.1.6 Alternative alignments and design options have been studied at the early stage of this assignment. Findings in the study are summarized in the Section 2.4 of this report. The alignment and design option proposed in this report, as compared with other alignments and design options, has minimum predicted impact.

12.1.7 There are no scheduled concurrent designated projects (DP) in the vicinity of the proposed tunnel portals, intakes or tunnel alignment during the construction and operation phase.

12.2 Environmental Legislation, Standards and Guidelines

12.2.1 The following Hong Kong SAR Government legislation, standards and guidelines are relevant to the assessment of impacts to fisheries associated with the construction and operation of the project:

l Environmental Impact Assessment Ordinance (Cap.499) and the Technical Memorandum on Environmental Impact Assessment Process (EIAO TM);

l Fisheries Protection Ordinance (Cap. 171) and its subsidiary legislation, the Fisheries Protection Regulations;

l Marine Fish Culture Ordinance (Cap. 353) and associated subsidiary legislation; and

l Water Pollution Control Ordinance and its supporting regulations and statements.

12.3 Environmental Baseline Methodology

12.3.1 The tunnel alignment is located southwest Hong Kong Island and the outlet is on the coastline and the subtidal zone. The study area for fisheries is the same as for marine water quality impact assessment (Figure 12.1), which include 5 Water Control Zones (WCZs) within HKSAR (listed below), as well as any areas likely to be impacted by the Project:

l Eastern Buffer WCZ;

l Western Buffer WCZ;

l Victoria Harbour WCZ;

l Southern WCZ; and

l Second Southern Supplementary WCZ.

12.3.2 A literature review was conducted to provide information on existing conditions in the study area, and to identify fisheries resources that may be affected by the Project. Literature review included Government and private sector reports, independent and Government published literature and academic studies. Literature review included the following:

l Port Survey 96/97;

l Port Survey 2001-2002; and

l AFCD annual report.

12.4 Assessment Methodology

12.4.1 Impacts to fisheries were assessed based on the guidelines in Annexes 9 and 17 of the TM, the consultants’ local knowledge and international standards.

12.4.2 The significance of fisheries impacts is evaluated based primarily on the criteria set forth in Annex 9 of the TM:

l Nature of impact;

l Size of affected area;

l Loss of fisheries resources/production;

l Destruction and disturbance of nursery and spawning grounds;

l Impact on fishing activity; and

l Impact on aquaculture activity.

12.4.3 Impacts are generally ranked as "minor", "moderate" or "severe", although in a few cases a ranking of "minimal" (less than "minor") may be given. The ranking of a given impact would vary based on the criteria listed above. For example, an impact might be ranked as "minor" if it affected only common species and habitats, or if it affected only small numbers of individuals or small areas, whereas it might be ranked as "severe" if it affected rare species or habitats, large numbers of individuals or large areas. The major factors giving rise to a ranking are explained in the text. As noted in Annex 16 of the TM, a degree of professional judgement is involved in the evaluation of impacts.

12.5 Baseline Conditions

12.5.1 The outfall location falls within the Western Buffer WCZ. Although there are some sites of fisheries importance within the fisheries assessment area (Fig. 12.2), none of them is located in the vicinity of the outfall structure.

Sites of Fisheries Importance

12.5.2 The following sites of fisheries importance are located at the study area and are shown in Figure 12.2:

l Ma Wan Fish Culture Zone.

l Cheung Sha Wan Fish Culture Zone.

l Sok Kwu Wan Fish Culture Zone.

l Lo Tik Wan Fish Culture Zone.

l Po Toi Fish Culture Zone.

l Tung Lung Chau Fish Culture Zone.

12.5.3 No other designated or recognized sites of fisheries importance lie within the study area.

Capture Fisheries

12.5.4 Detailed data on HKSAR capture fisheries in the fisheries study area were taken from the results of Port Survey. Port survey is the most comprehensive fisheries study conduced by AFCD every few years.

12.5.5 Within HKSAR waters, the highest yields for local fisheries were mainly derived from the eastern and northeastern coasts as indicated in the AFD Port Survey 96/97. While the western waters were comparatively less productive.

12.5.6 The study area for the present project covers the “Western Harbour”(SE03), “Southern Lantau” (SE04), “Victoria Harbour” (SE05) and “South of Hong Kong” (SE07) sectors, as well as the majority of the “Junk Bay” (SE06) and “Po Toi” (SE08) sectors. In 96/97 Port Survey, the two partially covered sectors, i.e. “Po Toi” and “Junk Bay”, ranked relatively high out of the 12 sectors in Hong Kong, the 2^nd and 3^rd in terms of average adult fish production respectively. While the four fully covered sectors ranked between 5^th to 9^th .

Table 12.2 Fishing Areas within “South of Hong Kong” sector

Fishing Area		Area	Total Production	Total fish fry	Total value	Production /ha	Fish fry/ha	Value/ha
68	Stanley Peninsula W	926.21	80,188.21	36,800.00	1,848,235.12	86.58	39.73	1,995.47
69	Stanley Bay	19.72	\	\	\	\	\	\
70	Chung Hom Kok	507.61	59,856.14	14,720.00	1,089,993.47	117.92	29.00	2,147.31
71	Chung Hom Wan	117.73	1,997.33	\	144,966.66	16.97	\	1,231.40
72	Round Island	239.95	22,809.78	\	352,524.63	95.06	\	1,469.14
73	South Bay	48.22	384.66	\	30,208.33	7.98	\	626.51
74	Repulse Bay	61.62	1,003.16	\	38,875.00	16.28	\	630.86
75	Middle Island	120.47	1,651.20	\	66,958.33	13.71	\	555.81
76	Deep Water Bay	98.16	1,545.06	\	73,458.33	15.74	\	748.34
77	Sham Shui Kok	233.57	14,543.42	\	170,701.09	62.27	\	730.84
78	Aberdeen Channel	59.88	\	\	\	\	\	\
79	Aberdeen Harbour	12.12	\	\	\	\	\	\
80	Ap Lei Pai	145.05	7,346.01	\	391,966.18	50.64	\	2,702.32
81	Ap Lei Chau S	145.90	5,591.21	\	316,640.09	38.32	\	2,170.21
82	Ap Lei Chau N	24.61	5,821.20	\	301,304.35	236.55	\	12,243.82
83	Tin Wan	35.79	6,249.26	\	341,748.79	174.60	\	9,548.38
84	Magazine Island	33.21	\	\	\	\	\	\
85	Wah Fu	78.76	\	\	\	\	\	\
86	Telegraph Bay	255.05	11,444.92	\	222,956.52	44.87	\	874.16
87	Sandy Bay	233.09	11,444.92	\	222,956.52	49.10	\	956.51
88	Mount Davis	417.87	\	\	\	\	\	\
96	Pak Kok	873.35	64,686.73	55,544.34	1,211,979.53	74.07	63.60	1,387.73
97	Po Law Tsui	402.88	85,552.86	62,904.34	3,073,371.69	212.35	156.14	7,628.49
98	Ha Mei	1,653.66	246,277.79	79,464.34	6,078,196.23	148.93	48.05	3,675.61
99	Tai Kok	2,133.91	407,638.34	86,824.34	6,884,342.15	191.03	40.69	3,226.16
100	Tung O	1,381.00	306,778.49	19,977.14	3,934,045.66	222.14	14.47	2,848.68
101	Sok Kwu Wan	340.97	100,692.29	28,551.54	2,247,670.52	295.31	83.74	6,592.05
102	Luk Chau	351.32	43,320.01	5,257.14	644,311.91	123.30	14.96	1,833.95
112	East Lamma Channel	507.12	\	\	\	\	\	\

12.5.11 19 locations within the Study Area were reported as home ports in the 2001/2002 Port Survey, including Ma Wan, Tsuen Wan, Peng Chau, Silver Mine Bay, Cheung Chau, Yung Shue Wan, Sok Kwu Wan, Lo Tik Wan, Po Toi, Tung Lung Chau, Yau Ma Tei, Lei Yue Mun, Causeway Bay, Shau Kei Wan, Chai Wan, Tai Tam, Stanley Bay, Deep Water Bay, and Aberdeen.

12.5.12 Aberdeen is the largest homeport in Hong Kong and also is the closest one to the outfall location. In the 96/97 Port Survey, there are 701 out of the 4857 fishing vessels in Hong Kong claiming Aberdeen as home port, and 187 of them are under 15m in length. The fish catches from this homeport ranked second among the 38 ports in Hong Kong (3,609,883.74 kg) and the value of the catches ranked the first (HK$ 46,349,644.22). There are also 241fishing vessels from Aberdeen interviewed for the 2001/2002 Port Survey.

12.5.13 It is anticipated that the focal area for capture fisheries issues would be the marine portion of the present project Study Area, in which the outfall located and the area covering 500m either side. The marine portion of this Study Area for the Project is located in Fishing Area 86 Telegraph Bay. This fishing area is of 255.05 ha in size. The production is 11,444.92 kg (= 44.87 kg/ha) at the value of HK$ 222,956.52 (= 874.16 HKD/ha). Among all fishing areas in Hong Kong, it ranks 129^th in terms of production and 143^th in terms of value. There is no fish fry production from this fishing area.

12.5.14 The 1996-97 data reveal that the dominant taxa reported from the area as landed catches are typically low value. In rank order (by weight), the top 10 fish types caught in the Telegraph fishing area were Acetes spp. (silver shrimp), Argyrosomus spp. (Croaker), Ilisha elongate (Whiter herring), Pseudosciaena crocea (yellow croaker), Eleutheronema tetradactylus (Threadfin), Siganus oramin (rabbitfish), Stromateoides spp. (Pomfret) Gymnothorax spp. (Moray eel), Harpodon nehereus (Bombay duck), and Platycephalus indicus (Flathead).

12.5.15 As reported in the Port Survey 2001/2002 (AFD 2003), the catches from the direct impact grid cell (L15 in Figure 12.4) were among the lowest in Hong Kong (> 0 $ <= 50 kg/ha) in adult fish production. Fishing vessels operated in this grid cell include shrimp trawler, gill netter, hand liner and Sampan. There are only less than 50 fishing vessels operated in this grid cell, among them, only less than 10 are over 15m in length.

12.5.16 There is also no fish fry collected within this grid cell.

12.5.17 Among the 10 species of major fisheries products in 2000-2001 Port Survey, the most abundant species in this grid cell is rabbitfish which has a production of 5-10 kg/ha.

12.5.18 For the value of the production, this cell is among the lowest in Hong Kong waters (<= 500HK$/ha).

12.5.19 These figures demonstrate that the direct impact cell is of low importance to capture fishing operations in Hong Kong.

Mariculture

12.5.20 The predominant type of mariculture in Hong Kong is marine fish culture which involves rearing of marine fish from fry or fingerlings to marketable size in cages suspended by floating rafts usually in sheltered coastal areas. Common species under culture include green grouper, brown-spotted grouper, Russell's snapper, mangrove snapper, red snapper, cobia and pampano.

12.5.21 Marine fish culture is protected and regulated by the Marine Fish Culture Ordinance (Cap. 353) which requires all marine fish culture activity to operate under licence in designated fish culture zones. Currently, there are 26 fish culture zones occupying a total sea area of 209 ha with some 1370 licensed operators. The estimated production in 2004 was about 1,540 tonnes which catered about 9.1 per cent of local demand for live marine fish.

12.5.22 Water quality within Marine FCZ is regulated under the WPCO and its supporting regulations and statements. Within Fish Culture Subzones, the dissolved oxygen level should not be less than 5 mg l-1 for 90% of the sampling occasions during the year; values should be calculated as water column average (arithmetic mean of at least 3 measurements at 1 metre below surface, mid-depth and 1 metre above seabed). In addition, the concentration of dissolved oxygen should not be less than 2 mg/l within 2 metres of the seabed for 90% of the sampling occasions during the year, and the annual geometric mean of E. coli should not exceed 610/100 ml.

12.5.23 Out of the 26 Fish Culture Zones (FCZs) in Hong Kong, there are six gazetted FCZs within the Study Area for the Project. FCZs inside the fisheries assessment area include Ma Wan FCZ, Cheung Sha Wan FCZ, Sok Kwu Wan FCZ, Lo Tik Wan FCZ, Po Toi FCZ and Tung Lung Wan FCZ. Lo Tik Wan FCZ is the nearest FCZ from the Project area.

12.6 Fisheries Sensitive Receivers

12.6.1 Fisheries sensitive receivers identified within the Study Area includes the followings:

l Grid cell L15; and

l Six fish culture zones, particularly Lo Tik Wan FCZ.

12.7 Impact Assessment

Identification of Environmental Impacts

12.7.1 The construction activities at tunnel portals and intake shafts will include site preparation and clearance, excavation, intake structures and tunnel portal structure construction, utilization of ancillary equipment at tunnel portals to support tunnel construction, material handling and blasting at portals (or intakes if necessary).

12.7.2 Potential sources of impact during construction phase include:

l Fishing ground loss; and

l Water quality.

12.7.3 Potential sources of impact during operational phase include:

l Water quality.

Construction Phase

12.7.4 This section of the report considers the potential impacts of project construction on capture fisheries and mariculture. The construction activities at western tunnel portal will include site preparation and clearance, excavation, tunnel portal structure construction, utilization of ancillary equipment at tunnel portal to support tunnel construction, material handling and blasting at portal.

Fishing ground loss

12.7.5 In order to reduce the inland traffic constraint, at the western portal at Kong Sin Wan, a temporary barge berthing point will be constructed for the transportation of excavated spoil from proposed drainage tunnel and supporting materials or equipment for tunnel construction. The dimension of this temporary pier would be 11m x 40 m. An area of 440m² shallow sea area would be occupied by this berthing point. Construction of works for the proposed drainage tunnel will be finished within 4 years. The area occupied by the berthing point would not be available for capture fisheries activities during this period.

12.7.6 After the tunnel construction works are finished, the temporary berthing point will be removed. A stilling basin will be constructed on the shore while an armor rock panel (25m x 25m, = 625m²) just outside the outlet of the stilling basin will be placed directly on the existing seabed without the need to carry out any dredging works. This panel is to enhance the protection of the seabed from scouring. Each armor rock is about 1 tonne in weight (about 1 m in size) resting on muddy/sandy bottom.

12.7.7 Given the low fisheries production and catch value in the Grid cell L15, and the small size of fishing ground (maximum 625m²) affected, the impact is ranked as minimal.

Water quality

12.7.8 At western portal, a pier as an alternative marine access for barge will be built at Kong Sin Wan. This will involve approximately 4,500 m³ of imported fill materials and may lead to re-suspension of sediment and disturb the sandy bottom. Suspended solids created in berthing point construction and demolition would increase the turbidity of the waters, which could bury sessile organisms, and thus reduce the amount of light reaching the sea bed. Furthermore, those suspended solids might settle on the surface of benthos. Resuspension of sediments would also reduce oxygen levels and potentially release pollutants into the water column. All these consequences may affect the health and survival of marine organisms, including commercial species, as well as mariculture species if the sediments are carried to Fish Culture Zones by currents. These impacts, short-term and localised in nature, however, would not be expected being severe to the marine communities in Kong Sin Wan and all FCZs, due to the small scale of the works. Impacts would be short-term and would be largely self–corrected after project completion without active restoration efforts. The impact would be ranked as minor. Mitigation measures for these impacts would be required.

12.7.9 Siltation is also a major impact upon the water quality generated by different construction works. Construction of the tunnel and the ground surface structures of the western portal would cause considerably small volume of site runoff, taking into account the limited extent of earth works.

12.7.10 Construction site runoff can contain sediments, organic substances, oil, grease and solvents that can affect marine ecology. These substances can increase turbidity, decrease oxygen levels and introduce contaminants, potentially injuring or killing benthic organisms (such as shellfish) and driving mobile organisms (such as fishes) away from the vicinity and thereby causing a short-term degradation of fisheries resources. If the pollutants are carried to Fish Culture Zones by currents, mariculture species might also be affected.

12.7.11 Impacts would also be short-termed. The impacts of such runoff would be ranked as minor and mitigation measures would be required.

Operational Phase

12.7.12 This section of the report considers the potential impacts of project operation on capture fisheries and mariculture.

Water quality change

12.7.13 The water quality assessment showed that the operation phase effluent from the drainage tunnel would have only limited and localized impacts on marine water quality. The water quality modelling simulated the 1 in 2 years and the 1 in 50 year design storm event outfall hydrographs for the discharge from the Western Portal. Three parameters, i.e. suspended solid, E. coli, and salinity, were simulated and presented in figures. Two fisheries culture zones in Lamma (i.e. Lo Tik Wan: 4 km from the outfall, and Sok Kwu Wan: 5.5 km from the outfall, see Table 12.3) were selected as fisheries sensitive receivers (SRs) for water quality assessment due to their relatively closer distances to the outfall location. All other FCZs are farther away from the outfall than these SRs (Table 12.3). Fisheries resources in Grid Cell L15 is not considered as a SR because, although in the vicinity of the outfall, they could avoid the areas to be temporarily affected and return afterwards. Cultured fish in designated FCZs are therefore more of concern to those transient water quality changes.

Table 12.3

Distance from water quality fisheries sensitive receivers and other Fish Culture Zones to the outfall location

Site	Distance from the outfall (km)
Water Quality Fisheries Sensitive Receivers
Lo Tik Wan	4 km
Sok Kwu Wan	5.5 km
Other Fish Culture Zones
Ma Wan	12 km
Cheung Sha Wan	13 km
Tung Lung Chau	16 Km
Po Toi	17 Km

12.7.14 Predicted suspended solids concentrations were plotted to show areas affected by suspended solids for the 1 in 2 year and 1 in 50 year storm events (see Figure 4, 5, 12 and 13 in Appendix I - water quality modelling results). For both the flood and ebb tide scenarios these show that the plume is generally confined to the landward coastal waters on the west coast of Hong Kong Island from Green Island to Ap Lei Chai. For SS the plots show that the nearer FCZs (Lo Tik Wan and Sok Kwu Wan in Lamma Island) are not affected by the plume for either tide scenario (ebb or flood) or discharge magnitude (1 in 2 years or 1 in 50 years).

12.7.15 Tables 7.8a and 7.8b of Water Quality Assessment Chapter showed that for both Lo Tik Wan and Sok Kwu Wan, no net increase of the maximum and cumulative SS concentrations are predicted for all flood and tide scenarios from the model and therefore, all predicted results are well within the Marine WQOs. As these two nearer FCZs are not affected by the SS, all other FCZs which are farther away are also not affected by the SS. Nevertheless, as an early alert on any irregularities on the SS concentrations, DSD will liaise with WSD for referencing the data from SS sensor/turbidity meter or other appropriate equipment which is being considered by WSD for installation at the future Cyberport seawater intake site. If any increase in SS concentration is recorded, the Operation and Maintenance staff of DSD will investigate the cause and take the appropriate measures.

12.7.16 Maximum relative concentrations of E. coli higher than 100 cfu/100ml are limited to the immediate vicinity of the discharge point. E. coli concentrations up to 95 cfu/100ml are limited to a narrow strip along the west coast of Hong Kong Island. However, for all modelled flood and tide scenarios no exceedance in terms of maximum cumulative concentrations will occur at any of the Water Quality Sensitive Receivers including Lo Tik Wan and Sok Kwu Wan (see Tables 7.9a and 7.9b). The impact is considered insignificant. As these two nearer FCZs are not affected by E. coli, all other FCZs which are farther away are also not affected.

12.7.17 The minimum salinity plots (see Figure 10, 11, 18 and 19 in Appendix I - water quality modelling results) again show the areas affected by the storm water discharge. These areas are limited to a narrow strip along the west coast of Hong Kong Island. The most affected waters are the surface layer in areas located immediately adjacent to the Western Portal. Salinity will be higher in the middle and bottom layers of the water column owing to the density gradient. In the flood scenarios, the impact is stronger to the SE, while in the ebb scenarios the NW direction is affected the most. It should be noted that the background salinity shows a spatial gradient, due to the presence of the Pearl River plume. In all cases, the impacted areas are smaller in the 1/2 years scenarios, due to the smaller discharge water volume.

12.7.17

12.7.18 The change in salinity at the ecological SRs are assessed with the results shown in Tables 11a and 11b for the 2-year and 50-year storm events, respectively. The tables show the maximum difference between the modelled baseline condition and the modelled implementation scenario (which is the accumulation of the baseline and the proposed tunnel’s discharge plume). Pak Kok is just 2.5 km from the outfall and is closer than the two FCS SRs. The WQO requires that “human activity should not cause the natural ambient salinity to change by more than 10%”. For both magnitude storm events and tide scenarios the change in salinity is less than 1% and therefore meets the WQOs. Furthermore, the change in salinity resulting from the freshwater plume discharged from the Western Portal is significantly less than the natural daily fluctuations in salinity at the SRs. As the Pak Kok ecological SR is not affected by the salinity, all FCZs including Lo Tik Wan and Sok Kwu Wan are farther away are also not affected.

12.7.19 The magnitude of the changes in water quality and the extent of the affected area by the operational discharge are very limited. Fisheries resources within Grid cell L15 is not going to be impacted by transient water quality changes. None of the Fish Culture Zones would be affected. Even Lo Tik Wan at the northeastern of Lamma, the nearest FCZ to the outfall, is outside the affected range. All other FCZs inside the Study Area is farther away from the outfall and the affected area. No impact on the FCZs is expected. The impacts from the operation of the drainage tunnel is thus ranked as minimal. The construction and operation phase impacts were summarised in Table 12.4 below.

Table 12.4 Summary of fisheries impacts within the Study Area

Impacts	Due to	Duration	Receiver	Severity	Need for mitigation
Construction phase
Permanent fishing ground loss (625m²)	Outfall and stilling basin	Permanent	Capture fisheries	Minimal	No
Temporary fishing ground loss (440 m²)	Temporary berthing point	Temporary	Capture fisheries	Minimal	No
Marine water quality	Resuspension during construction and demolition of berthing point; construction of outfall and stilling basin Dumping, spilling, and leakage of chemicals from vessels or equipment	Temporary	Capture fisheries and mariculture	Minor	Yes
Operational Phase
Marine water quality	Increase in suspended solid, nutrient, E.coli. and freshwater during operation	Permanent	Capture fisheries and mariculture	Minimal	No

Cumulative Impacts

12.7.20 This section of the report considers the potential cumulative impacts from other concurrent projects in the study area.

12.7.21 There are no scheduled concurrent designated projects (DP) in the vicinity of the proposed tunnel portals, intakes or tunnel alignment during the construction and operation phase.

12.7.22 As stated in the results of water quality assessment, no cumulative impact on the marine water quality from other project is expected. There is also no other concurrent marine works project in the vicinity of the tunnel outfall. Therefore, no cumulative construction and operational fisheries impacts are likely to arise from this DP.

12.8 Mitigation Measures

Construction Phase

12.8.1 Potential sources of impact during construction phase include:

l Site runoff;

l Suspended solid during the construction and demolition of the berthing point; and

l Construction of the stilling basin.

12.8.2 Site runoff will be controlled by general site practices during the construction.

12.8.3 Silt curtain will be deployed during the construction and demolition of the temporary berthing point. With the deployment of silt curtains around the berthing point area, adverse water quality impact associated with the filling would not be anticipated. No marine water quality impact is anticipated.

12.8.4 The invert of stilling basin will be found at -5.4 mPD. A cofferdam in the form of pipe-pile wall is to be constructed outside the stilling basin prior to the construction of basin. The cofferdam will be dewatered to provide a working space for the construction of stilling basin. The boulders from the seawall will then be removed by landbased grabs. The increase of suspended solid level will thus be minimal. Upon completion of the construction the cofferdam will be removed from site and the seawall will be reinstated.

Table 12.5 Mitigation measures recommended for

Construction phase impacts of the Project and the effects

Impacts	Mitigation measures and effects
Site Runoff	Good Site practices
Construction and demolition of temporary berthing point	Deployment of silt curtains
Construction of stilling basin	Cofferdams Dewater the site prior to using land based grab.

12.9 Residual Impact

12.9.1 The construction of the outfall and stilling basin will result in some loss of fishing ground (subtidal muddy bottom habitat). However, the size of the loss is small (625 m²) and the fisheries importance of the area is low. This loss is not expected to have a significant negative impact on the capture fisheries. Residual impacts on habitat loss are acceptable.

12.9.2 No residual impacts on the FCZs are predicted. This is due to no overlaps between the area of waters affected during the operational phase and the FCZs.

12.10 Environmental Monitoring and Audit

12.10.1 Besides the EM&A for water quality, no specific EM&A programme for fisheries would be required for the Project.

12.11 Conclusion

12.11.1 The above discussion should make it apparent that the construction and operation of the Project has no significant impacts on capture fisheries and mariculture. A well-planned program of site practices should be able to maintain the impacts to acceptable level. Specific fisheries monitoring during both the construction and operational phases will not be needed.

12.12 References

AFCD 1998. Port Survey 96/97. Agriculture, Fisheries and Conservation Department, Hong Kong SAR.

AFCD 2003. Port Survey 2000/2001. Agriculture, Fisheries and Conservation Department, Hong Kong SAR.

AFCD 2004. 漁農自然護理署年報2001-2002. Agriculture, Fisheries and Conservation Department, Hong Kong SAR.

Sector		Area	Total adult fish production	Total fish fry production	Total value	Adult fish production per ha	Fish fry production per ha	Value per ha	Rank (adult fish production)	Rank (fish fry production)	Rank (Value)
SE 03	Western Harbour	4,613.93	629,799.80	30,645.16	18,388,312.08	136.50	6.64	3,985.39	5	8	3
SE 04	Southern Lantau	22,225.53	2,424,556.01	22,983.87	56,048,596.62	109.22	1.03	2,521.81	7	10	7
SE 05	Victoria Harbour	5,852.39	399,579.94	\	10,752,679.78	68.28	\	1,837.31	9	\	8
SE 06	Junk Bay	3,265.92	541,921.43	250,753.99	18,713,498.21	165.93	76.78	5,729.93	3	3	1
SE 07	South of Hong Kong	11,458.81	1,486,822.99	390,043.18	29,687,411.10	129.75	34.04	2,590.79	6	5	6
SE 08	Po Toi	11,085.61	2,182,594.79	178,484.39	40,543,058.80	196.89	16.10	3,657.27	2	7	4

Area

Total Production

Total fish fry

Total value

Production /ha

Fish fry/ha

Value/ha

Impacts

Due to

Duration

Receiver

Severity

Need for mitigation

Construction phase

Permanent fishing ground loss (625m2)

Outfall and stilling basin

Permanent

Capture fisheries

Minimal

No

Temporary fishing ground loss (440 m2)

Temporary berthing point

Temporary

Capture fisheries

Minimal

No

Marine water quality

Resuspension during construction and demolition of berthing point; construction of outfall and stilling basin Dumping, spilling, and leakage of chemicals from vessels or equipment

Temporary

Capture fisheries and mariculture

Minor

Yes

Operational Phase

Marine water quality

Increase in suspended solid, nutrient, E.coli. and freshwater during operation

Permanent

Capture fisheries and mariculture

Minimal

No

Table 12.5 Mitigation measures recommended for

Construction phase impacts of the Project and the effects

Impacts

Mitigation measures and effects

Site Runoff

Good Site practices

Construction and demolition of temporary berthing point

Deployment of silt curtains

Construction of stilling basin

Cofferdams

Dewater the site prior to using land based grab.

Permanent fishing ground loss (625m²)

Temporary fishing ground loss (440 m²)